Volume rendering:

* Multithreaded volume light cache

While the render process itself is multithreaded, the light cache pre-process 
previously wasn't (painfully noticed this the other week rendering on some 
borrowed octocore nodes!). This commit adds threading, similar to the tiled render - 
it divides the light cache's voxel grid into 3d parts and renders them with the 
available threads.

This makes the most significant difference on shots where the light cache pre-
process is the bottleneck, so shots with either several lights, or a high res light 
cache, or both. On this file (3 lights, light cache res 120), on my Core 2 Duo it now 
renders in 27 seconds compared to 49 previously.

http://mke3.net/blender/devel/rendering/volumetrics/threaded_cache.jpg

1 files changed, 18 insertions, 8 deletions

diff --git a/source/blender/render/intern/include/render_types.h b/source/blender/render/intern/include/render_types.h
index 65bb12e059d..8dbdde77726 100644
--- a/source/blender/render/intern/include/render_types.h
+++ b/source/blender/render/intern/include/render_types.h
@@ -202,9 +202,9 @@ struct Render
 
 	struct Object *excludeob;
 	
-	ListBase vol_precache_obs;
 	ListBase render_volumes_inside;
 	ListBase volumes;
+	ListBase volume_precache_parts;
 
 	/* arena for allocating data for use during render, for
 		* example dynamic TFaces to go in the VlakRen structure.
@@ -404,13 +404,6 @@ typedef struct StrandRen {
 
 /* ------------------------------------------------------------------------- */
 
-typedef struct VolPrecache
-{
-	struct VolPrecache *next, *prev;
-	struct Material *ma;
-	struct ObjectRen *obr;
-} VolPrecache;
-
 typedef struct VolumeOb
 {
 	struct VolumeOb *next, *prev;
@@ -423,6 +416,23 @@ typedef struct MatInside {
 	struct Material *ma;
 } MatInside;
 
+typedef struct VolPrecachePart
+{
+	struct VolPrecachePart *next, *prev;
+	struct RayTree *tree;
+	struct ShadeInput *shi;
+	struct ObjectInstanceRen *obi;
+	int num;
+	int minx, maxx;
+	int miny, maxy;
+	int minz, maxz;
+	int res;
+	float bbmin[3];
+	float voxel[3];
+	int working, done;
+} VolPrecachePart;
+
+
 /* ------------------------------------------------------------------------- */
 
 struct LampRen;